The proposed research will examine the potentiating effects of alcohol (ethanol) on traumatic injury. The relationship between alcohol and injury incurred by drivers in motor vehicle crashes will be investigated, taking into account other variables known to be associated with driver injury, such as speed and type of crash, degree of vehicle deformation, driver age and sex, and safety belt usage. Motor vehicle injuries account for approximately half of all accidental deaths in the U.S. and constitute the second most costly health problem facing the nation today. Alcohol is involved in approximately half of all motor vehicle fatalities. Although alcohol has long been associated with injury, the presumed relationship has been attributed to impaired judgmental-perceptual-motor functioning. However, there is evidence from experimental animal studies that alcohol increases the degree of injury from a given traumatic event. To what extent such a relationship holds for humans has not been clearly established. While the relationship cannot be investigated experimentally, nevertheless there is one type of injury to humans that occurs in large frequencies and for which there is independent information that can provide estimates of the impact experienced by the victim, namely injuries from motor vehicle crashes. Not only is there information on impact-related variables, but also there are usually estimates of alcohol involvement. In many instances precise measures of bac are available. This study will include three phases. Phase I will consist of a review and integrative summary of relevant literature. Phase II will consist of analyses of two years of N.C. crash data as well as the National Accident Sampling System file. Phase III will be a clinical study of patients receiving emergency treatment for motor vehicle injuries at a Level I Trauma Center. The three phases of the study will complement each other and provide the most comprehensive information available on the relationship between alcohol and traumatic injury in humans. The findings should have implications for alcohol education, patient care, and the validity of the animal models for investigation of the relationship between alcohol and injury in humans.